Ohmic contact for p-type group II-IV compound semiconductors

DETAILED DESCRIPTION The present invention is an improved p-type ohmic contact for Group II-IV semiconductors.
The contact includes a p-type Group II-VI semiconductor device layer and a p-type Group II-VI crystalline semiconductor contact layer on the first side of the device layer.
A conductive electrode layer characterized by a Fermi energy is on the contact layer.
The contact layer is doped, with shallow acceptors having a shallow acceptor energy, to a net acceptor concentration of at least 1.
times.
10.
sup.
-17 cm.
sup.
-3, and includes sufficient deep energy states between the shallow acceptor energy and the electrode layer Fermi energy to enable cascade tunneling by charge carriers.
In a preferred embodiment the semiconductor device layer includes a ZnSe semiconductor layer.
The electrode layer includes a gold layer.
The contact layer is doped with nitrogen to a concentration of 1.
times.
10.
sup.
-19 cm.
sup.
-3.